Mobile computers can be used in various power environments, e.g., in a car, in an office, on an airplane, etc. Accordingly, computers come equipped with power adapters that can be plugged into sockets on the wall of an office, the bulkhead of an airplane, the cigarette lighter of a car, etc. to power the computers and thereby save battery life for times when no socket is available.
As understood herein, in each of these examples uniform power is not provided to the computer, because the power available from a plane, for instance, does not match the power available from an office wall socket. For instance, many laptop computers ordinarily draw ninety watts, but an airplane power system may be designed to supply only seventy five watts. Under these circumstances, the present invention recognizes the desirability of informing the computer about the power environment in which it finds itself, so the computer can tailor its own operations accordingly.